JP2002200734A - Blanket cylinder for printing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a novel blanket cylinder for printing capable of improving productivity of printing by shortening time for stopping an offset press as short as possible without increasing a time and a labor hour in a work for replacing the blanket. SOLUTION: The blanket cylinder for printing feeds a long-sized band-like blanket B from a feeding roll 2 installed in a hollow cylindrical blanket cylinder body 1 to an outside of the body 1 via a slit 11, circulates in one circle along the peripheral surface 10, then returns the blanket to an interior through the slit 11, and winds the blanket on a winding roll 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel printing blanket cylinder used in a printing machine such as an offset printing machine.

[0002]

2. Description of the Related Art Conventionally, in an offset printing machine, printing is performed in a state where a flat blanket is wound around and fixed to the outer periphery of a cylindrical blanket cylinder main body forming a blanket cylinder (rubber cylinder). FIG. 3 is a cross-sectional view showing a general example of a structure in which a flat blanket B is wound around the outer periphery of the blanket cylinder main body 91 and fixed.

In the above fixing structure, first, mounting bars 92, 92 are fixed to both ends Ba, Ba of the blanket B, which is cut to a length of one circumference of the blanket cylinder main body 91 and a small length, respectively. Next, with the blanket B wound around the blanket cylinder main body 91, both ends Ba and Ba are inserted into the inside of the blanket cylinder main body 91 through the slits 911 provided in the blanket cylinder main body 91. Next, the mounting grooves 93a of the pair of tension bars 93, 93 rotatably mounted in the blanket barrel main body 91,
The mounting bars 92, 92 are inserted into and fixed to 93a, respectively. By winding up the tension bars 93 in the direction indicated by the solid arrow in the drawing, the blanket B is mounted and fixed on the peripheral surface of the blanket barrel main body 91 with a constant tension.

To replace the blanket B, first, the offset printing press is temporarily stopped, and the blanket cylinder main body 91 is stopped.
Remove the side cover (not shown) that closes the end of, exposing the fixing portion. Next, after the tension bars 93, 93 are rewound in the opposite direction to release the tension, the mounting bars 92, 92 are removed from the tension bars 93, 93, and the blanket 1 is removed. Then, a new blanket 1 is mounted and fixed to the blanket cylinder main body 91 in the same procedure as described above.

[0005]

As described above, conventionally,
Once to replace the blanket, the offset press had to be stopped and the blanket removed from the blanket cylinder. And the above work took time and effort. For this reason, printing cannot be performed while the offset printing press is stopped, and there has been a problem that printing productivity is reduced.

[0006] In particular, when printing is performed on a plurality of surfaces by one printing machine, it is necessary to replace a blanket every time the printing surface changes, so that printing productivity has been significantly reduced.
The present invention provides a novel printing blanket cylinder that can improve printing productivity because the time required to stop an offset printing machine can be reduced as much as possible without requiring time and labor for replacing blankets. Is to provide.

[0007]

According to the first aspect of the present invention, there is provided a blanket cylinder main body having a hollow cylindrical shape and having a slit connecting the inside and outside of the cylinder at at least one position on the circumference thereof. In order to wind a long strip-shaped blanket, a pay-out roll installed inside the blanket drum main body and a pay-out roll were fed through a slit to the outside of the blanket drum main body, and made one round along the peripheral surface thereof. And a take-up roll installed inside the blanket cylinder main body to wind up a long strip-shaped blanket returned to the inside of the blanket cylinder main body through the same or a different slit as described above. .

According to the first aspect of the present invention, a long strip-shaped blanket wound in advance on a feeding roll is provided.
For example, the paper is fed from the feeding roll by a length corresponding to one round of the blanket cylinder. At the same time, the used portion of the blanket is simply taken up by the take-up roll and stored in the blanket cylinder main body, thereby completing the blanket replacement operation. In other words, as described above, conventionally, the side cover that closes the end of the blanket cylinder main body is removed, and the blanket replacement work that has been done manually with the blanket fixing part exposed is This can be performed only by rotating the take-up roll.

[0009] Therefore, it is possible to reduce the time and effort for replacing the blanket and to shorten the time for stopping the offset printing machine as much as possible. In some cases, without stopping the offset press,
Blankets can be changed during the printing interval. For this reason, especially in the case where it is necessary to replace a blanket every time a printing surface changes in order to perform printing on a plurality of surfaces with one printing machine, it is possible to significantly improve printing productivity.

The invention according to claim 2 is the printing blanket cylinder according to claim 1, wherein a porous elastic layer functioning as a compressible layer of the blanket is provided on the peripheral surface of the blanket cylinder main body. In the printing blanket cylinder according to claim 1, when the blanket wound around the feeding roll runs out, the offset printing press is temporarily stopped and the end of the blanket cylinder main body closed, as in the related art. Remove the lid to expose the pay-out roll and the take-up roll. Then, a blanket replenishing operation is required, such as taking out the feeding roll and winding a new blanket, or replacing the old feeding roll with a new feeding roll wound with a blanket.

According to the second aspect of the present invention, the blanket compressible layer can be omitted by providing a porous elastic layer functioning as a blanket compressible layer on the peripheral surface of the blanket cylinder main body. For this reason, when performing printing that requires the use of a blanket having a compressible layer, the thickness of the blanket can be reduced by the amount of the compressible layer, so that a longer blanket can be wound around the payout roll. . Therefore, the number of times of performing the above-described blanket replenishing operation can be reduced as much as possible, and the printing productivity can be further improved.

[0012]

FIG. 1 is a sectional view showing an embodiment of a printing blanket cylinder D according to the present invention. As shown in the figure, a printing blanket cylinder D of this example is formed in a hollow cylindrical shape, and has a blanket cylinder main body 1 having a slit 11 connecting the inside and outside of the cylinder at one location on the circumference thereof, and the blanket cylinder main body. Blanket B installed inside 1
And a take-up roll 3 for taking up a blanket B, also installed inside the blanket cylinder main body 1.

The blanket B is formed in a long strip shape having a length of, for example, twice or more the circumference of the blanket barrel main body 1, and is wound around the feeding roll 2.
Then, the leading end is fed out of the feeding roll 2 to the outside of the blanket cylinder main body 1 through the slit 11 as shown by a solid line arrow in the figure, and is caused to make one round along the peripheral surface 10 of the blanket cylinder main body 1. After returning to the inside of the blanket cylinder main body 1 again, the blanket is wound around the winding roll 3.

In the drawing, reference numeral 4 denotes a winding roll 3 for unwinding the blanket B from the unwinding roll 2 and winding the blanket B on the winding roll 3 as described above.
Is a motor for rotating in the direction indicated by the dashed line arrow in the figure. The rotation of the shaft 41 of the motor 4
Is transmitted to the take-up roll 3. Reference numeral 6 denotes a rotation axis of the blanket cylinder main body 1. A drive mechanism such as a motor may be arranged outside the blanket cylinder main body 1. In this case, for example, when the blanket cylinder 1 stops at a fixed position such as a printing machine, a gear or a joint that can transmit power from a driving mechanism provided outside may be attached to the shaft of the take-up roll 3.

Although not shown, the feeding roll 2 includes:
It is preferable to provide a mechanism for applying a constant tension to the blanket B that has made one round along the peripheral surface 10 of the blanket cylinder main body 1 against the winding force caused by the rotation of the winding roll 3. As such a mechanism, in addition to a friction mechanism that simply makes the feeding roll 2 difficult to rotate, a slight rotational force is applied in a direction opposite to the rotation direction (indicated by a dashed line in the drawing) of the feeding roll 2 by the action of a spring or the like. There are various conventionally known mechanisms, such as a mechanism for pulling the feeding roll 2 in a direction opposite to the feeding direction of the blanket B by the action of a spring or the like.

The slit 11 of the blanket cylinder main body 1 is
Usually, it is preferable to form along the axial direction of the cylinder,
It may be formed so as to be inclined so as to have a predetermined angle with the axial direction. In the example, in one place of the blanket cylinder main body 1,
Although the slit 11 serving as the exit and the entrance of the blanket B is provided, a slit serving as the exit of the blanket B and a slit serving as the entrance may be separately provided. When the printing blanket cylinder D having the above-described components is used for printing in which a blanket having a compressible layer is required, for example, as shown in FIG. It is preferable that a porous elastic layer 12 functioning as a compressible layer of the blanket B is provided on 10 and the compressible layer of the blanket B is omitted. The reason is as described above.

The elastic layer 12 can be configured similarly to the compressible layer of the blanket B. That is, (A) a foaming agent or hollow microspheres are dispersed in rubber, and in the case of a foaming agent, simultaneously with vulcanization,
Or a layer having an independent pore structure formed by foaming by heating before or after vulcanization, or (B)
A particle having a continuous pore structure formed by dispersing particles such as salt in rubber and vulcanizing the rubber and then eluting and removing the particles with a solvent such as water is used as the elastic layer 12. it can. In particular, the layer (A) having an independent pore structure is preferable because it has excellent durability and can reduce the time and effort for replacement.

The elastic layer 12 may be formed directly on the peripheral surface 10 of the blanket cylinder main body 1, or may be formed by covering the blanket cylinder main body 1 with a cylindrical one. In particular, if the cylinder of the elastic layer 12 is merely covered without being adhered to the blanket cylinder main body 1, replacement is easy. It is preferable to form an antifouling coating such as a silicone resin on the surface of the elastic layer 12 in order to prevent the generation of dirt and maintain print quality.

As the blanket B combined with the elastic layer 12, for example, as shown in FIG.
And a blanket B having a single-layer or multiple-layer base fabric layer B2 and omitting the compressible layer as described above. As shown in FIG. 2B, a compressive layer B3 having the same configuration as the elastic layer 12 is provided on the blanket B,
The elastic layer 12 of the blanket cylinder main body 1 may be omitted. In this case, however, it is preferable to provide a base fabric layer B4 on the lowermost surface of the blanket B, which is in contact with the peripheral surface 10 of the blanket body 1, as shown in FIG.

When the printing blanket cylinder D is used for printing which does not require the use of a blanket having a compressible layer, as shown in FIG.
2 and the compressible layer B3 may be omitted. When printing is performed by mounting the printing blanket cylinder D of this example having the above-described components on a printing machine such as an offset printing machine, first, as shown in FIG. Wrap around. The length of the blanket B is, for example, the circumference of the blanket cylinder main body 1, the length from the feeding roll 2 to the slit 11, and the length from the slit 11 to the winding roll 3, and the printing surface on which the blanket B is to be replaced. And the allowable length that can be wound around the feeding roll 2 is appropriately set.

Next, the front end of the blanket B wound around the feeding roll 2 is fed out of the blanket body 1 through the slit 11, makes one turn along the peripheral surface 10, and then passes through the same slit 11. When returned to the inside of the barrel main body 1 and wound around the take-up roll 3, continuous printing is possible. Also, after performing continuous printing in this state, for example, when the printing surface is changed as described above, the printing press is temporarily stopped,
Alternatively, the motor 4 is driven again using the printing interval, and the winding roll 3 is rotated in the direction indicated by the dashed line arrow in the figure.

Then, by this rotation, the used old portion of the blanket B is taken up by the take-up roll 3, and a new portion is taken out from the pay-out roll 2 and supplied to the peripheral surface 10 of the blanket cylinder body 1. As a result, the exchange of the blanket B is completed, and continuous printing can be performed again. The continuous printing and the exchange of the blanket B are repeated, and
When the blanket B wrapped around the printing machine is nearing the end, the printing press is temporarily stopped, a side cover (not shown) for closing the end of the blanket cylinder main body 1 is removed, and the feeding roll 2 is removed.
And the winding roll 3 are exposed.

Then, as described above, take out the feeding roll 2 and wind a new blanket B, or
Alternatively, replenishment work such as replacing the old feeding roll 2 with a new feeding roll 2 around which the blanket B is wound is performed. Then, continuous printing can be performed again until the blanket B wound around the feeding roll 2 disappears. As described above, according to the printing blanket cylinder D of this example, the blanket B wound around the peripheral surface 10 of the blanket cylinder main body 1 can be replaced easily and in a short time with a new portion fed from the feeding roll 2. Therefore, even if a single printing press prints on multiple sides,
Even when the blanket needs to be replaced every time the printing surface changes, the printing productivity can be significantly improved.

The configuration of the printing blanket cylinder D of the present invention is not limited to the embodiment described above.
Various design changes can be made without changing the gist of the present invention.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an example of an embodiment of a printing blanket cylinder of the present invention.

FIGS. 2A to 2C respectively show a surface of a blanket cylinder main body used for the printing blanket cylinder of the above example,
It is sectional drawing which shows the example of a layer structure of the blanket combined with it.

FIG. 3 is a cross-sectional view showing an example of a blanket mounting structure in a conventional blanket cylinder.

[Explanation of symbols]

 D Blanket cylinder for printing 1 Blanket cylinder main body 10 peripheral surface 11 Slit 2 Feeding roll 3 Winding roll B Blanket

Claims (2)

[Claims] 1. A blanket cylinder body formed in a hollow cylindrical shape and having a slit connecting the inside and outside of the cylinder at at least one position on the circumference thereof, and a blanket cylinder body for winding a long strip-shaped blanket. From the feeding roll installed inside, and from the feeding roll, feed out to the outside of the blanket cylinder main body through a slit, make one round along the peripheral surface, and then return to the inside of the blanket cylinder main body through the same or a different slit as above. And a take-up roll installed inside the blanket cylinder main body in order to wind up a long strip-shaped blanket. 2. The printing blanket cylinder according to claim 1, wherein a porous elastic layer functioning as a compressible layer of the blanket is provided on a peripheral surface of the blanket cylinder main body.